I can't imagine laminating roll media on the flatbed that often. We do it when we need to laminate 60" but that's it.... Like once a month and we hate it.
With a flatbed printing most of your printing will be direct to substrate I presume. So the roll to roll printer is going to be for stickers / substrates you don't print on, wall graphics / other graphics? I'd hate to do those on a flatbed. What do you do when someone orders 500 stickers? Print it on 8 ft sections? Then unwind 8 ft of laminate, manually Lam the vinyl, unwind another 8 ft, etc? Think about it... If you print 50 ft of vinyl, not only do you have to split your prints up into 8 ft sections, you have to manually unwind the overlam 7 times, manually put it on 7 times... By the time you've laminated 10 ft it'd have all been laminated on a roll laminator.
A flatbed laminator is great - but if you're using it as a work table to do a ton of cutting and stuff, it turns into a not so great laminator. We use our flatbed 8 hours a day mounting aluminum / trimming signs... Brand new it's great,but now there's some flat spots where we use the table a lot that causes slight bubbling when laminating. Buy a new $750 cutting matt (because anything over a 48" cutting matt is crazy expensive...) And it's back to laminating perfectly... Until the pressure from mounting 1000 signs causes anotherndjp.
It may take you years to get to that point... but if you're also using it as a work table, it may take you even less. Every cut / knick / non smooth surface will make your laminating slightly worst -
It's the same reason we don't use our laminators for mounting - laminate is very finicky, the more pristine the rollers are .. the better your laminating goes.
At the very least, I'd buy the cwt and a $2-3000 cheapo laminator to do all the laminating on. Or budget it in knowing you should be buying it sooner than later.
Unless you plan on printing under 8 ft of roll vinyl a day . And if that's the case you should be outsourcing anyways.