Well, first of all, you'd better consider that IDS/IPS is not intended to protect only one system. IDS/IPS's can detect exploit attempts and take immediate countermeasures (typically by terminating session or shutting down a relevant vlan if integrated in a more complex NAC/IPS system).
Using it on a single machine is...well, it doesn't really makes sense IMHO..
It's all about personal firewalling.
Otherwise, you can consider checking entry level UTM appliances and buy one...there are many offers from Juniper, Checkpoint, Zyxel..If you want something which deals effectively with a lot of threats and assures you good performances at a reasonable price, you can even check Netasq products...they're terribly effective and efficient at a reasonable price. Almost nobody knows that company even if it's the NATO UTM choice for their networks...