I want a modernized SAR type setup. I am trying to decide if I would be better off keeping my Gen II 13” pistol or getting a 16” Gen 1 rifle and SBR’ing it. The pistol’s brace tube definitely needs to be swapped out if I keep it, and I will attempt to find a lighter forend for it as well. Here is how I am currently weighing the pro’s and con’s:

Pistol:
1. Needs multi slot buffer tube
2. Sights
3. Forend

Rifle:
1. Needs SBR stamp
2. Barrel cut, recrowned, and threaded.

Outside of not waiting for another tax stamp approval, I think that the amount of money spent will be about the same. I am open to suggestions.

Using your current Gen 2 pistol would be the route that I'd go. OCCAM sights would be a good, low-profile addition.   But, I haven't heard of any replacement forends for the Gen 2.  Have you?
I am guessing that you have a line on a Gen 1?  They are pretty uncommon nowadays, compared to the Gen 2 models.  Availability (since you already have one) would be my reason to go with the Gen 2 and you could always SBR at a later date.
I keep hoping that the rock n lock 5.56 will come in as a 13 inch pistol.