Academy kits of the UH-1 early series (also released under the MRC label since MRC is the importer) are nice but not so easy builds. Plenty of PE available. Panda makes the H/N and they are crap compared to the Academy. Dragon re-released the Panda kits with better decals and some basic PE... lipstick on a pig sort of thing.
For the Cobra, again look at Academy. AFV Club has the same kit with Taiwanese modifications under their label. Eduard does some nice PE.
Resin accessories exist for most kits but Cobra Company, the one I liked best, ceased trading.
All the above are the 1/35th scale kits. In 1/32nd, you may find the Monogram and or Revell Huey and Cobra. Both are basic models which need a lot of work.
Regards,