I suggest you scratch that M4 itch lol welcome to the forum!
You have to weigh the options, cost, and your tools/ability to each option.
With the 1014 you get the collapsible stock (which is currently worth 800 to 1000 bucks) and you get a fixed choke barrel (barrel is not threaded for chokes) is that is something you prefer - I have not seen the info about the 1014 barrel being thicker per se, just that it is not threaded for chokes. Downside is that you do not have the 3 position recoil tube. So in order to make the collapsible stock functional on the 1014, you will have to buy a new recoil tube - which are spotty to find right now, and then will have to put in some serious work to get the old tube off safely. You are going to need some serious heat/torque/work. Use the search function here, there are some good walk throughs. All that being said, it is still possible to do it all. You will still have the limited magazine tube to deal with and remove but a heat gun and some patience and you can easily take care of that on your own.
With the 11707, you will have a 3 positon recoil tube under the stock, so that hard work is done. You will have to find and buy a collapsible stock (800-1000 bucks). With the barrel you will get one that is threaded for chokes if that is something you prefer. You will still have to deal with taking off and replacing the limited magazine tube but again, not too hard to do.
Parts wise, the collapsible stock is what it is. Gunbroker and Ebay are the wild west. For the magazine tube there are lots of fantastic options - on this forum SOCOMguy tubes are well regarded, Dave's Metal Works makes great tubes, CarrierComp and Freedom Fighter Tactical make great titanium tubes that will shave some weight off the gun, Briley makes a carbon fiber tube that looks pretty nice on the gun too. Many options available - prices range from less than 100 bucks up to well into the 200/300 range for a full length tube.
I am not a lawyer and did not stay at a Holiday Inn last night but a note you may or may not know about is 922(r) which is compliance parts. If you replace the magazine tube and go for the collapsible stock, you will need a total of 4 American made parts on the gun. The magazine tube would be 1, a new follower in the magazine tube would be 2. That means you would need 2 more American parts from a specific parts list replaced - so that means parts inside the trigger or a new trigger guard and parts inside the trigger, etc. GREAT info here: Learn 922(r) – Freedom Fighter Tactical
Others will chime in on which option might be best but for me personally, I took option 2 and did the 11707 and am replacing and setting it up the way I want but you might feel that the 1014 option is better for you/your situation/skills and abilities.
