Like others have said, you actually have a few options, based on what you want to do and how much you want to spend.
If you want to build a kit, you have the resin Spulse kit mentioned above. Kevin's build is just amazing and is the best bet if you want to build a static model. Your looking at $200 with a light up counter.
Spulse Rifle
Not a kit, but you could try and find an Icons PR. Static resin PR with no functions. The counter was a sticker though. Watch for recasts however.
The Harry Harris Aliens Collection & Archive: Pulse Rifle
If you want to build a PR with some working features, but still avoid an airsoft version, you can collect parts from Matsu and others. This will be more expensive but will give you a more accurate PR. You would need to source the shrouds and GL from Matsu, if he still has them. You would need to get your metal bits (barrel, vent, stock, etc.) from other vendors. Other than the Spulse, no one makes a "complete" PR kit with all the parts. Prices can vary, but expect to spend at least $400 and more.
Still a kit, but moving into the airsoft area now. You can get the PR kit that is intended to be built around an airsoft Thompson. It includes all the PR parts to turn a Thompson into a PR. You could, theoretically, use a resin Thompson as a base for this. You would not be able to use certain features of the kit, such as the working counter that requires the airsoft be functional. You're looking at $200 for the kit and would need to source a Thompson of some sort (resin/airsoft).
Evike.com Airsoft Guns - External Parts | Evike.com Airsoft Guns - Conversion Kits | Evike.com Airsoft Guns - Thompson / M1A1 Series Kits | Evike.com Airsoft Guns - Alien Pulse Rifle Conversion Kit for Thompson M1A1 Series Airsoft AEG |
Your next option would be the airsoft PR already assembled on an airsoft Thompson. These are the Matrix/Snow Wolf PR that are dominating the forums now. Some minor inaccuracies, but you get a kick arse replica that fires airsoft BB's and has a working ammo counter. About $300 give or take.
Evike.com Airsoft Guns - Airsoft Guns | Evike.com Airsoft Guns - Evike Custom Guns | Evike.com Airsoft Guns - Others | Evike.com Airsoft Guns - <b>Matrix Limited Edition Custom Alien Pulse Rifle Airsoft AEG</b> |
Probably the last option would be a the HCG replica of the PR. very accurate in appearance but not functional other than the GL handle sliding back and forth. You do get metal shrouds which to a lot was the major draw factor in these. Be aware that however that there were major quality control issues with these. The main one was the GL drooping down. The other was the counter not lighting up properly. You can find these in the $500-$800 range on auction sites and in the Junkyard.
http://www.therpf.com/f9/hcg-aliens-hero-m41a-pulse-rifle-modification-93717/
The ultimate would be an SD Studios replica. Very expensive, but none better for accuracy.
The Johanson Collection: "Armat M41-A Pulse Rifle", by SD Studios