I really would advise against putting a "budget" optic at a 45degree offset. I have used a T-1 in the 45 offset and it is a really cool set-up that is pretty functional once you get the hang of it. To roll it quickly takes a little work but once you develop that muscle memory, transition is pretty quick. I have gone to the ACOGTA31RMR set up which I like as well (similar to the 45 offset just a different motion - it is nice that you don't affect the standard up/down trajectory of the round but you don't get near the cheekweld that you can with the 45 - so... both have their strengths and drawbacks).
However, the 45degree offset mount puts that red-dot in an extremely vulnerable spot. It is sticking off the rifle in a way that makes it easy to bang around on cover and if you drop the rifle on that side, the offset optic is going to take a large majority of that impact. The Aimpoint T1 is the best way to go but is pricy so I understand that is out of the question. The trijiRMR is very solid in this config but is also pricy. The cheapest I would go would be a Vortex Sparc. Unless you are just going to cradle it as you cary it out to the range and then be super super gentle, I would strongly advise against that sightmark.