a big single wont have any more torque that a 300cc twostroke...
those high performance 4strokes cost alot more to maintain compaired to a twostroke.
If you want something cheaper to own and maintain you should be looking at a drz450 motard as they have decent service intervals and are reliable as fook. dont get a highly strung motard unless you want to maintain it.
If you want an affordable holligan bike that will scare the shite out of you and wont need expensive services, Id get a KTM300 of Gas Gas 300.
Id only go for a bigger set of wheels once you found the limit with the stock width rims...
you'll have to be pushing your bike hard to find the edge of the stock tyres...
and road tyres for mx rims are CHEAP!!! 200bucks for pirelli scorpion front and rear seat :D
just depends how cool you want to look :D
You'd be forgiven for getting fat tyres, it does look pretty cool
I just love the way that a motard changes you... in the tight stuff you just cant help sticking your leg out...
haha