You can race on anything - but you might want to think about how you'll place. Before you buy a bike, consider what sort of courses you'll be racing on. If they're rock-strewn DH or DS courses, then the Kikapu will last for a handful of rides before **** starts breaking off at random. A few things to look for in a XC race bike:
- light weight. You'll have to drag that thing up hills. Every pound you save on the weight of the bike has the potential to save you time, unless the bike lacks...
- durability. The lightest bike in the world won't help you win unless it holds together long enough to get you across the finish line.
- efficiency. As much energy as possible must be channeled from your body to the bike and then to the ground. Most race bikes are still hardtails because most race courses don't require full suspension for an efficient ride. YMMV.
- handling. This is different for everyone. Most XC bikes have 71/73 head/seat angles with 100mm of travel or less. This setup works for a lot of people. Again, YMMV.
I'd suggest you see what the local racers are on, and get something similar to what they have, but in your price range. I'd guess that most are on hardtails. Look at what the top 10 guys are on. If most are on hardtails, I'd suggest you go with that.