New Leaf Springs 69 F250

[RMVA]

I have a '69 F250 crew cab and want to buy new front and rear leaf springs with a 2.5" lift. There seems to be many companies building springs, which offer the best ride for on/off road use?

With stock springs, whats the biggest tire you can put on a 1969 F250 (w/o a lift)?

Thanks!