Note: There are a number of WWII Airsoft weapons that are available but the only ones that are mentioned below with a write up are weapons that we have used and would recommend .
M1A1 Thompson - AEG (battery powered) and the manufacturer is Tokyo Mauri. This is the most easily obtained Airsoft weapon of all the WWII weapons. This weapon is very reliable. It performs very well right out of the box. Remember that the Thompson was usually issued by Officers and NCOs.
M1 Garand - Gas Powered and manufactured by Marushin. This is a beautiful rifle. Built to be very realistic. However, it is limited as an Airsoft weapon. The clips only hold 8 bbs and the clip ejects from the rifle once its empty. Again this is realistic but there is a good chance that you may lose a clip or two.
M1 Garand (Alternative) - This is a Tokyo Mauri M14 that has been converted to a M1 Garand. The conversion can be done in a few hours and the cost can be approx. $75 to $150 cdn. The weapon is an AEG and you continue to use the M14 Mags. You can also modify the mags so that it only protrudes 1/8 of an inch out from the rifle. The shortened mags hold 15 bbs.
M1 Carbine - Gas Powered and manufactured by Marushin and fires an 8mm bb. This weapon came in two versions, the full wood stock and the para stock version for the Paratroopers. This weapon is very hard to obtain and the mags are even harder to find. Here is a link to a step by step conversion to a para stock.
M3A1 Grease Gun - Gas Powered and manufactured by Hudson. The least expensive of all the WWII weapons but then you get what you pay for. Most of this weapon is made of plastic.
M1918 Browning Automatic Rifle (BAR) Will be updated in the near future.
Bren Will be updated in the near future
M1911A1 Colt - Gas Powered. There are several manufacturers of this hand gun and they come gas powered or spring powered. The two manufacturers that I would stick with are Tokyo Mauri and Western Arms. This hand gun was the standard sidearm.
Kar98 - Gas Powered and manufactured by Marushin and Tanaka. This weapon fires 8mm bb. This is one of the more expensive airsoft weapons at approx. $750. The Marushin version is very realistic, including the brass shells that you load the bbs in and then load into the weapon. This may not be the best weapon for airsofting because you may be more worried about losing the shells then hitting your target but it's as real as it gets. Read the review for the Marushin Kar98 here.
MP40 - AEG and manufactured by TOP and a few other manufacturers have now come out with their version, notable Marushin. I should add that as nice looking as the Top MP40 the two that I have seen have not been very reliable.
Mauser M712 - Gas Powered and manufactured by Ho Feng Corporation (HFC). Marushin also has a version of this weapon as well. The HFC Mauser M712 pistol, also known as the 'Broomhandle' because of its pistol grip, is a heavy piece. It is constructed entirely out of metal with only a few plastic parts in the non-critical areas. The grips have an excellent wood finish on them and are difficult to determine whether they are plastic or actual wood. Read the review for the HFC Mauser M712 here.
Luger - Will be updated in the near future.
Beretta M1934 - Gas powered and manufactured by Western Arms. Will be updated in the near future.