i havent used either one (but i do use an integy auto tire truer), and from looking at both truers you posted, i suggest getting the one with the replaceable arbor (the first link) so you can true foams for different types of cars. also, the motor in this truer looks to be a larger, heavier duty type compared to the other one (2nd link). you do have to buy a separate arbor for each type of rim that you will be truing (eg. touring, pan, 1/8, etc.) and that will cost you at least $15-$20 each arbor.
i think one of the truers you posted has a built in hex adapter (the 2nd link) that can be used for touring cars only
why not buy the integy automated truer? if you buy online (tower has discount codes), the discounted price may be pretty close to the manual truers
also, you may find additional tire truer info in this thread (from nitro onroad forum) ...