UserM4

Hello, New here on Saiga-12. I've been gathering as much information about Saiga conversions as possible and am about to start ordering for a Saiga that I don't even own yet! I still haven't decided on whether I should get a 7.62x39 or a 5.45x39. Anyways, that's a whole different topic. I want to install an Ultimak rail or handguard with a Vltor tube adapter and a CTR stock. Which Magpul riser should I get to closely mimic an AR cheek weld with AR irons/optic from my parts bin? TIA Steve