noob needing help with permant sights on SIG 516

[jtoth]

I have the Sig 516 SCM model. It came with the STS-081 Mini Red Dot Sight. I would like to leave this red dot on the rifle and co-witness with some good permanent fixed iron sights. My questions are:
1) Because of the piston adjustmant nob in the front is there anything I need to be worried about when picking my front sight (I would like to use the original M4/AR15 front sight)?
2) Is there a better front sight for this set up then the original front sight?
3) What would a good fixed rear sight be for this set up?

Lastly I am on a budget and don't have $400+ to spend on sights. I would like to stay below $200, the further below that the better, but I do understand you cant go too cheap. Thank you for any help you can provide me with. (The photo doesn't have the red dot as its a picture from the web)

[kmrtnsn]

If you are looking for an original style sight tower/gas block you are out of luck, your pistol system precludes its installation. If you are looking for a good pair of folding back-up iron sights (BUIS) then I recommend you take a look at a set of Troy's. Troy is the OEM manufacturer of folding BUIS for LaRue, BCM, and others. As far as co-witnessing with the Chinese made SIG optic that is going to be a bit of a problem as I believe it is sold with the rifle minus any kind of riser, making the use of a fixed height BUIS a problem.

[Anchor Zero Six]

This https://danieldefense.com/components-parts/fixed-front-rear-sight-combo.html should work out well for ya.

LMT and YHM also make a similar set which have an A2 style rear sight. I prefer the DD due to them NOT having the large thumb screws on the sides.

[jtoth]

Well those DD sights do look good, and the price is right, I have a few other questions maybe you can help with.
1) Is there a benefit to using those DD style sights that mount on the rail versus a front sight that mounts to the barrel?
2) If need be I can just add a riser then to co witness with the SIG STS-081 Mini Red Dot Sight correct?

[Anchor Zero Six]

1) Not at all. The rail mounted sights are the correct height to be the same as a barrel installed front sight tower. Some pic railed gas blocks are lower than the handguard rail which would require a correct height front buis but from the attached pic it looks like yours is on the same plane so you will be fine.

2) Correct on the riser for the mini dot. Depending on how close a T1 clone the sig sight is you might be able to use a T1 mount/riser.

[jtoth]

Thank you for the info