Unless the PSU is a good Corsair or SeaSonic (combo) then 'modular' means zip. I typically find 'combos' are pushing one or more crap component, and only a few combos are 'good.' Generally if $30 stands in the way of me getting what I want then it's a no brainer decision to get what I want.
The Sabertooth Z77 (series) is very good and the MOBO's are built very well, and they come with a 5 year warranty. Reviews and Reviewers only have a short time to conclude anything about a particular component, and worst they're use to one BIOS and flub-up in a different BIOS -- invalidating their benchmarks. As long as you stick to the top 3 you're fine: ASUS, Gigabyte & MSI. My preference is ASUS.
About the only discussion I steer clear of are cases, as long as there's nothing obviously wrong with the case.
i didn't realize you get much advantage inoverclocking ram, but thanks now i under stand. If i get the sabertooth i have to get a crosair carbine 400r. if i get the ud3h i have to get the cm trooper. i here the 400r is fine, im just a bit worried about the size and amount of air flow, compared to the trooper.
thank you all for all the added information you have given me, now my final question is knowing that the sabertooth and the 400r case go together, is it still better than the ud3h and the trooper. my guess is yes but i wont to know what every one else thinks. and buy the way this is for gaming, im using a 3570k cpu, and gtx 660 graphics. also when would i need more than a 700w psu.