Hey everyone, I'm needing some help. I'm looking at buying a Bushnell TRS-25. I want to use this with a MagPul MBUS flip up rear sight.

My questions are -

What riser size will I need to get it to co-witness with the flip up rear sight and front post?

Has anyone used the UTG LE Rated riser or the UTG High Profile Riser? I keep seeing this two mentioned as being ones that can co-witness together. But that has all been on YouTube videos and I'm not sure I can trust what they are saying.

Do you guys know of any other brand of risers that you would recommend that won't break the bank? My budget for rear sight, red dot and riser is $100-$160.

Do you guys know of the best place to order these from? I have looked at PSA, Cheaper Then Dirt, and Amazon. The prices for the rear sight range $45-$55. The red dot is $79-$95. The riser has been $10-$17. So if you know of something in my price range please let me know.

Thanks everyone.

I bought my Bushnell TRS-25 from Amazon.
An option is to buy a mount with the sight as a package.
The MEDIUM riser will give you an exact co-witness with the "iron" sights.

The Amazon Bushnell is a great deal and it's being sold by Amazon, not a third party seller.

http://www.amazon.com/Bushnell-Trophy-TRS-25-Reticle-Riflescope/dp/B00200E0HM/ref=sr_1_1?ie=UTF8&qid=1407784773&sr=8-1&keywords=bushnell+trs-25

Look down the page to the "Frequently Bought Together" area.  You want the UTG medium height riser to give a true co-witness.
Bought together the sight and medium riser cost $88.00 and you get FREE shipping.  That's the best deal I found and if you have a problem, Amazon will take care of it.

Thanks I will check the link out and that is a heck of a deal on it. I also like that it is being sold right from Amazon. I have had problems in the past with books being torn while in shipping and a Kindle that went back after a year and amazon replaced them. So I do like dealing with them. Good info to know it is right from them.

Are you wanting an absolute co-witness or lower 1/3?  Riser height choice makes a difference.   The high riser package for the TRS-25 (RDS plus high riser) gives you a lower 1/3, which most people want.   I prefer absolute, but it's purely a matter of choice.

I'm trying to figure that out. I'm not sure but I'm thinking I would want it to be true co-witness. Can you explain it more to me? This is my first adventure into using a red dot or any type of optic.

What is your front sight?  Is it fixed or flip up?  If it is fixed, it may take up too much of your field of view if you absolute cowitness.  If it folds and you normally keep it down, an absolute cowitness may give you a pretty clear field of view, both eyes open.  

I think I'd go with the Primary Arms micro red-dot instead of the Bushnell TRS-25. I think they might even be the same price:

https://www.primaryarms.com/Primary_Arms_Micro_Dot_With_Fixed_Base_p/md-fbgii.htm

Not sure about the UTG risers though. Quick detach are always my preference.