175/65 might be a bit better but sometimes too much offset is too much. And I'm not sure that ratio would even make that much difference.

Maybe the treads on the rally tires protrude more than stock tread so you might have a win there.

But yeah talk to your shop, tell them you'll buy from them but you want to try the different profiles. I'd remove two of the rims and take them into the shop to have two different profiles fitted (one on each) so you can take them home to try out. You could take the back ones in just be sure they're the same rim width etc as the front ones.....no point bringing in more variables.