So I'm looking at doing some conversions and I'm trying to source a few bits. Specifically, I could use some katanas, some overlapping plates (domaru style) and the like with which to convert some other HI into Domaru, and possibly some SMG options to create some different Ryuken to add to the one I got out of my army box. Anyone have any ideas where to get this style of bits, or maybe how to make some?
Styrene sheet for the overlapping plates. It comes in various thicknesses (from 0.25mm up to 3mm at least) and the 0.25 or 0.5mm is easily cuttable with a common modelling knife. You'll need some polystyrene cement to go with it (and superglue and GS to get a good mate to the metal infinity figures). Or you could try your hand at sculpting them from a putty like Greenstuff (or brownstuff). When I've made katanas for my JSA, I've used some styrene rod (1mm) that I've shaped into a flatter shape (and carefully bent into shape with hot water) and some tubing that fit around it (you can get tubing and rods that fit together like this at model stores - NOT gaming stores. Aircraft, ships, tanks, etc models).
Historical gaming models. If you're in the UK, try The Assault Group miniatures. They have both historical samurai bits and relatively modern firearms. The Ryuken SMG looks a lot like an MP5, which is listed in the Modern American section. You can also try Hasslefree Miniatures (also in the UK). Hasslefree even has clear resin not-Major and Not-Batou minis, though the clear resin versions are expensive. The metal versions are quite cheap. hfminis also makes a lot of conversion bits and interesting civilians. I have ordered from both before (and I'm in the US), never had a problem. I apologize for lack of links, but Forum Advertising Rules.
To add to Section9's comment hasslefree are also very good in terms of fitting scale to infinity minis.