Welcome Hosk13f,
I'm from WI and you CAN hunt grouse with a lab and be successful. In fact, I think it has made my labs hunt even closer because of early season cover as we prepare for the pheasant season.
I'm sure you already did, but hop on line and check out the Grouse Society projects in PA. I see several on line. Also see Lycome county is suggested as good cover. Not sure where that is from you but....adventures are fun. Often state DNR sights have bird maps. One is good for checking out cover and if its state owned. Google Earth works if you don't have OnX. National Forests here in WI are tougher because they don't log. County forests seem better because they do log. I have found the game manager for a region I want to hunt is invaluable. They will tell you about the area or make suggestions. Make that call after you decide on a general area.
I agree with the rest of the posts about cover. Think LINEAR. Seek out edges. Clovered trails early in season. Dense aspen cuts. Oak edges to more dense cover when the acorns drop. Always any creek with tag alders or any tag alder fingers without water. The ground is softer and cooler in the tag alders and good for early season warm days. Don't be afraid of OLD cuts that have grown up as long as there is good under growth. Often these fill up with hazel nuts.
I'm all over the place on this post, sorry.
Some food and cover thoughts that might help your search:
Look for diversity in the acreage you choose. ie. One with creeks and pines and some cuts.
Early season I hunt logging trails first because birds are eating green forbes found along the trails. Dense aspen cut edges with leaves ON as young birds are eating insects.
After the first hard frost, they seem to switch to red or grey osier Berrys. White berries on bushes often found along trails.
Easy to spot. If you find large areas of them just see if they are dropping. When they do the grouse will be there.
Keep acorn edges in mind when they drop.
Later in the season or winter they eat catkins and buds off of aspen, birch, and tag alders. I love places with tag alders and pines.
Grouse hunting is a lot of miles per bird. Last year there were some days that it was 1 flush per hour. Thats 7 flushes in a day! I say this because the dog doesn't get a lot of work sometimes. This might sound goofy but I've learned over the years when I hunt with a dogtrot is new to grouse, I shoot on those first flushes. You don't get clear glimpses of the bird in early season anyway and have to shoot through leaves BUT I have found if I shoot on those flushes, even if I don't see the bird my dog flushed, that my dogs start to figure out that is what we're after. They already know gun fire means something good.
Good luck and enjoy that pup.