I'm curious as to why you want side mounted bipod legs instead of a traditional bipod? The Vltor ones linked are at least good quality (UTG is generally chicom junk) but none of the side-mounted bipods allow for cant (other than adjusting individual legs which is a pretty gross adjustment) which is less than ideal if shooting from anything other than flat, level ground. Depending on what your use case is, I'd suggest a Harris, Magpul or MDT Oryx or Grndpod bipod (the Grndpod being my favourite of those choices). All of those are reasonably priced, effective bipods that have adjustable cant so that you can level your rifle in any conditions.