i would get the size tire you want, and limp it around til you can afford at least the rear set of gears. you might be suprised, awhotrods is running and 37's on his 90 4runner sas'd and stock 4.10's. i've driven it and it has plenty of power for the tires. he has driven it from sac to l.a. and back cruising down the I5 with no power problems.
Well put, get what you can afford for the time being. I sat on mine for awhile till I got my 5.29's and 36's.
But what gears were you planing on going with? Something that'll be good and streetable or something to crawl with?