I'd say if you're on limited budget, start by dealing with the threat you are most concerned about first. You can always add in other products later when your budget allows. (Watch out - after your first big save, this stuff gets real addictive real quick!)
So let us know what kind of trap you are most worried about being caught by, and that will help us guide you further. Please be specific - don't just say "all of them."
As you know bikes present a different set of challenges to a car. The next thing you need to think about is how you are going to receive the alerts on a bike. After all, the best detector in the world is not going to help if you don't know when it's going off.
You have to think about whether you want to see the alerts, or hear the alerts, or both.
If you want to hear alerts, do you have an intercom system that perhaps you can link your kit up with? Do you wear ear plugs, if not a simple earphone might be OK to get you started.
If you want to see alerts, bear in mind that the normal displays on the RD are pretty useless on a bike, especially in sunny conditions. If you wear a helmet, you should check out the wireless helmet displays like our own
Cheetah VizAlert.
If you do wear a helment and want to see alerts I'd recommend a very decent mid-range detector like the
Bel RX65, teamed up with the
Cheetah VizAlert Helmet display. This also gives you a degree of flexibility because when your budget allows you can add in a
Blinder Laser Jammer system. The VizAlert display is the only helmet display that works with jammers like the Blinder as well as some of the decent radar detectors.
Hope this helps.
On a different matter, if you haven't checked it out yet, I recommend you visit
Pashnit.com for details on some amazing NorCal group rides. Brilliant site.