I tell my patients to go for the cheapest one that you can still find heads for. The newer models only have minor changes. I have the first model and it works perfectly (although they are about to stop selling heads for it).
which sonicare brush do you recommend? i have always wanted one and there are so many styles to choose from.
Two suggestions I give all my patients:
1) Get a sonicare toothbrush, I have used one for 9 years and its the best thing I ever bought
2) Try an experiment. Floss for two weeks every day (skipping ruins the experiment). Your gums will stop bleeding. Gingivitis and bleeding gums are caused by bacteria. The bacteria releases acid, which causes an immune response to send defense cells, these cells cause the gums to swell, which makes them weak. If you remove the bacteria (brush/floss), your gums will shrink back to normal size, gain their strength back, and will be strong enough to to bleed when you floss.
Now, this assumes you floss correctly. 99% of my patients do not know how as no one ever showed them. You need to get the floss below the gumline, and floss up and down against the tooth (think of getting under the bacteria and pulling it out of the gums). Most people floss in and out, which is a completely worthless movement, does nothing, and ultimately causes people to think flossing does not work.
Try these two things and let me know what you think after two weeks. You might be surprised at what simple, correct home care can accomplish. :)