LPN to rn 2 year or 4 year?

I'm currently a full time LPN...and i want to pursue my education to get my RN degree. Is it easier to do the bridge program that some colleges have...it's an LPN to a 2 year RN degree program..advanced. Or, would it be better to just go straight into a 4 year program? The only thing is, i don't know if any of the 4 year programs offer the 'bridge' program..i may have to start from scratch. I also don't have all fo my pre-reqs done like chem or bio,, so i know i will have to take those too, even tho i do have an LPN license. What do you think is the better choice?