Re:
Given the model you have, it's hard but not impossible to find replacements.
Here are a couple, in black or silver, BCD 94mm, many teeth combinations
http://www.bike24.de/p195192.html
http://www.bike24.de/p195220.html
If you get a new chainset, and it's for mtb and triple, there are only 2 potential compatibility issues:
-big difference in teeth between your current set-up and the new one, that the front derailleur might not cope with. For example, if your current set up (likely) is 44-32-22, and you get a 48-38-28, you might have to move the derailleur upwards in the frame. No big deal
-each chainset is designed for an specific bottom bracket spindle width. If you buy it in the shop, they should order one that matches. For example, your current chainset might be for a 118mm bottom bracket, and the new one is for a 110m bottom bracket. If you buy it yourself, best is to remove your current chainset, measure the bottom bracket width, and then check in internet the specs for whatever you're looking for. Shimano usually includes the recommended width in their product specs. Worst case, a 5mm difference is usually no big deal, and if you finally need a new BB, the square taper ones cost about 12 EUR online.