Need suit advice

I am currently applying to business school and only recently realized I don't actually have a single decent suit which I would need for the interviews (hopefully) in the next month or so.  I haven't needed one yet since I am in the tech industry and have gotten by entirely with jeans and polo shirts.

I went to Nordstroms but couldn't find any suits there that were in the style I wanted and in my size.  I'm not looking for anything fancy in particular, just a dark navy with very subtle stripes and flat-front pants in a 38S.  I found things in other sizes that seemed fine but they didn't carry my size.

I would go the MTM route at Brooks Brothers or Nordstrom but unfortunately in 8 weeks all my interviews will be over.  I'm planning on visiting the Brooks Brothers tomorrow in case they have what I want, but given my experience today I'm not so sure I'll find it.  Does anyone have any tips on other places I can find decent suits that will fit me?  One thing I've thought is that maybe I could get a 38R suit and just get it tailored, but wasn't sure if that is problematic.

Appreciate any help I can get - thanks!

I'm in the Seattle area - on the eastside, in Bellevue. 

Sounds like I should stick to 38S suits only - thanks for the tip!

Yes, definitely factoring that in.  I think they don't start sending invites out until the end of the month, so if I can get the suit within a week or so (whether that is rush ordering online this weekend or picked up in store over the next week) I should be fine.

Ended up getting a suit at Brooks Brothers - I'm sure I paid more than I would have if I had time to spare for a deal to pop up, but given the time crunch it seems like it wouldn't be possible to have done any better. 

I think the stripes seemed pretty subtle and really help elongate my form: http://www.brooksbrothers.com/IWCatProductPage.process?Merchant_Id=1&Section_Id=418&Product_Id=1210034&Parent_Id=216&default_color=BLACK&sort_by=ratings&sectioncolor=&sectionsize=38 Short#null.  I ended up going with the charcoal with stripes since I wanted something darker than that specific suit's navy option.  To my (admittedly untrained) eye it looked almost like a navy with stripes.

I look at this as just one good suit that can get me through my interviews for now and I can always have to go back to for later.  I have plenty of time to build up a full wardrobe over the next few years, since I won't really need one again until school starts in a year.  Even then, I understand suits are only needed during recruiting events, so if I only buy one more suit over the next year I will probably be fine until an internship in the summer of 2013.  I think it is never a bad move to go for a suit that looks particularly flattering, right?