Best map to use is the easy question.
Suitable outfitter depends on which access point you start from, so we'd have to answer that after you settle on the route. I've been happy with every outfitter I've used in the Algonquin area.
Route options are the big one... I suggest letting yourself get lost in the above-linked map for a while and see what calls out to you. The most crowded lakes are generally the ones with direct access off Highway 60, and those that are a short portage away from them. Though you'll be going a few days in so you'll get past the crowds. The map includes some features that speak to how remote a lake might feel, such as developments (summer camps, lodges, cottages etc) and where motorboats are allowed. It also shows the main fish species. The lake and brook trout that dominate most interior lakes go deep in the summer and are difficult to catch without specialized gear, so if you just wanted to toss some tackle around on spinning gear and still catch something, consider including lakes that have bass or other warmer-water fish.

Remoteness in  August can be challenging. Remoteness in August while on a route that avoids long portages is probably a pipe dream. But on the other hand you've got a long trip planned, which will help!

With a 7-9 day trip you have many possible loop trips, but here's one to get you started. 

Access Point 3: Magnetawan

Night 1: I'll assume you likely won't have much time on the first day, so camp on Hambone or Daisy Lake.
Night 2: Work your way down the Petawawa River to Misty Lake. Longest portage 935 meters
Night 3: Continue to follow the Petawawa to White Trout, then paddle into Big Trout. Longest portage, 850 meters
Night 4: Stay on Big Trout again. You've got a long trip so a rest day is a good thing, and it's generally a good idea to bake such a day in in case of inclement weather that throws off your schedule. Lots to check out around Big Trout - it's a gorgeous lake. You won't be bored. 
Night 5: Backtrack to White Trout and set up camp. Very short easy day, no portaging. 
Night 6: White Trout to Timberwolf Lake via McIntosh Marsh and McIntosh Lake. Longest portage 745 meters. Mostly paddling, but you're now heading West so you could be paddling into the wind all day. 
Night 7: Timberwolf to Queer Lake. This is mostly to avoid back-tracking a stretch of the Petawawa you've already paddled, but in order to do that you've got a 2435 meter portage. But hey, it's now the 7th day of your trip, your food barrel is almost empty, and you'll have lots of portage experience by this point. No sweat. Or you can just paddle back up the Petawawa if you'd rather. 

Night 8: You can paddle out this day no problem, or you could camp on Ralph Bice and then head for the car the following day. 

This, basically. Map is Jeff's map, which Dan already linked you to. 




 

DanPM wrote:

How long did that other Big Trout route on your linked page take you, the one starting from Magnetawan?

To be determined. We're doing that in July. We have 10 days booked for it.
 

It's either starting somewhere on the North side, like yellowcanoe suggested, which is as remote as it gets in AP, but with plenty of  hiking en route, or you can start for instance at Magnetawan (#3) and spend at least 2 days in and 2 days back in populated areas before you get to more distant lakes like Burntroot, La Muir or Hogan. Another alternative: you can start at Tim (#2) and take the Nipissing R into the park (very few people travel the Nip) and return to #3 by Big Trout and Misty. Local outfitters could take care of car shuttle.

P.S. of course the Nip itself requires 3-4 lengthy portages but they are mostly flat and easy.

Last edited by EddyTurn (6/17/2016 1:08 pm)

Remote of course is subjective. It's often used to mean places you can only get to by bush plane or through days of unmaintained canoe routes. Algonquin obviously is not that. Maybe "solitude" or "wilderness feel" are better words for what the OP is looking for, but that is at least as subjective as well. Maybe living in downtown Toronto gives me a lower bar, but for me the "wilderness feel" of the area stretching east from Magnetawan is fine; it doesn't strike me as a "populated area" just because you do encounter other canoeists here and there along the route. It's an area with no motorized boats, public road crossings, or buildings, and neither is it the sort of canoe superhighway where you have to wait in line at portage landing. The only parts of Algonquin's route network that really don't feel wild to me are the campground and cottage lakes along Highway 60 and including the Joes.

So I like the routes suggested above. Although the Brent route is not on the side of the park you we're planning to go to (I assume driving distance is the issue), note that it has an advantage fishing-wise, namely walleye in the Cedar-Brent corridor. Few parts of Algonquin have walleye.

Last edited by DanPM (6/17/2016 7:48 pm)

Thanks all for the great route ideas. I am looking into a bunch of them. 

A friend recommended entering around Kiosk as another potentially good alternative. Does anyone have any thoughts/advice on routes from there?