Like others have said, there are the three Tamiya kits and the Fine Molds kits. Also RPM does the Type 79 which is a copy of the French Ft-17 that they used in the early stages of the war. I think Fine Molds makes more IJA tanks than the Japanese Army actually used! 
 The Fine Molds kits are some of the best 1/35 scale armor kits produced. The smallest, the Type 94 TK tankette is about the size of a 1/72 scale MBT. The largest is the Type 3 medium tank that was armed with a 75mm gun that someone on Armorama was building last year. They do the Type 94, Type 95, Type 97, Type 1 and Type 3. FYI, the Japanese labeled their tanks using the year of the Emperor's rule (or something like that). The Type 94 was developed in 1934, Type 95 in 1935...Type 1 in 1941, Type 3 in 1943.
The reason why there are not a lot of Japanese armor kits is because there wasn't a lot of Japanese tanks. During WW2 the IJA was still basically a foot army. They had very little mechanization (hence the lack of softskins) and thought of the tank as mainly an infantry support weapon.
Pacific armor has not been missed. Italeri has embraced the AMTRACs, given us a PTO USMC Sherman and even Tamiya's original M4A3 Sherman had the Classy Peg markings of a US Army tank used in the Pacific.
Add to that the Japanese tanks done by the Japanese companies Tamiya and Fine Molds, and you will see that they cover just about all the variants of IJA tanks. There is a hole though. The special purpose vehicles and amphibious vehicles used by the Japanese are sorely missed. Probably not big enough of a market to justify producing injection molded kits of this nature.
As far as figures go, Fine Molds did at least 5 sets of figures from pilots to infantrymen to tank crewmen. Verlinden did some resin Japanese figures as well.