The main thing is, IMHO, is to FIRST buy the rig that you REALLY like and want.
After that it's simple, especially in the OP's case since he does not have a truck yet. Get the TV that will pull your rig choice without having to do mods or even come close to your TV 's limits. You'll thank yourself later...or maybe sooner!!
Lots of trucks can pull big weights but are you in a comfort zone being on the edge or marginal? Not me and those that really understand. (Sorry if that ruffles some feathers but it needed to be said).
To the OP: you may very well be OK with a SRW 1 ton for the rig you are considering and that is your choice after doing your due diligence, and it sure looks like you are doing that.
If you get to a point where you are 2nd guessing yourself step back take a deep breath and make the right decision not only for now but for the future.