I had similar issues when looking for the Academy 1/35 Huey Frog, I tried to find it all over the place, most sellers appear to be South Korean, Taiwanese, or Chinese and I had a number of ebay and other sales fall through.
I finally found one on a French site called Cherbourg Maquettes, but it cost me more than what is a reasonable price for a model kit I think (nearly £40 inc. postage).
My advice is if you want the Academy 1/35 UH-1C Frog (and everyone recommends it, and so would I) keep looking bud, they are out there but you have to look, and look, and look, and look, and look, and look...
The Academy 1/35 Huey Heavy Hog (the one with the square box of rockets armament system) seems slightly more readily available, so it depends on what you want to arm it with, I personally wanted the Frog because I wanted the XM21 Minigun system (and I like the Ace of Spade artwork) and it also comes with the weapons systems of the Heavy Hog kit.
If you want to go 1/48 and want a UH-1C/B about the only options you have are the Hobby Boss kit (which I've read is a poor kit), or the Revell (of Germany)/Monogram Huey Hog, they are readily available it seems, and cheap, but personally I think it's a shockingly bad kit for today, the fuselage fit is terrible, the plastic is seriously thin (seems like 10though plasticard in places, and we all should now how "floppy" that stuff is).
Personally I think Revell have a nerve selling it still considering it's such an old kit and is so bad (their HH-3E Jolly Green is a much better kit in terms of fitment and is from the same era)!
Other than that if you want a UH-1D I believe you have only the Panda/Dragon kits (same kit different producer as I understand it) in 1/35 and having looked around myself they're not readily available either (the UH-1N seems to be though).
In 1/48 I don't think there is a good UH-1D that is readily available, Lindberg make one but it's not a good kit from what I've read, you could keep your eyes open for an old ESCI (also sold as AMT/ERTL) UH-1D, or Italeri UH-1D but I've only seen a couple around (Ray (rotorwash) kindly gave me an ESCI UH-1D (before I started seeing them around) so perhaps others can do the same for you)
Don't know about in local hobby stores because I live in the UK (in N. Essex) and we don't have any decent LHS's here...
Basically for any UH-1C/UH-1D it seems like a case of keep looking, and hope you find one or some kind sole who has one in their stash is willing to sell you one
Hope that helps.