Best Heartworm, Flea/Tick Meds & Vaccines?

What brand of heartworm and flea/tick meds are best for the cavs? I don't want to give her too many "toxins" but I know some meds are necessary and helpful.
Currently, she's on "Worm Shield" (ivermectin 68mcg/pyrantel 57mg) for prevention of heartworms, ascarids (?), and hookworms.

Also, what are your thoughts on vaccinations? I prefer the route of choosing only the most necessary vaccines, but I haven't found much of a guidleline for that. Most resources I look into are either one extreme or the other. My current vet is a vaccine 'believer' and wants to administer them at the drop of a hat!
She's had vaccinations for Corona, Giardia, DAPPC (3 doses), Distemper/Parvo and Bordatella. The vet recommends the Bordatella vaccine EVERY THREE MONTHS and I can't take her to doggy day care unless I comply. We've opted to not return to that daycare!!!

As for her health, she's a normal, healthy, spayed and weight appropriate 7 1/2 month-old. We feed Blue Buffalo (high quality kibble, low allergens) and supplement with veggies. Parents are heart-clear and no known health concerns with her immediate lineage.

Any suggestions???

Melissa

I know my breeder and her vet are big believers in not over-vaccinating due to the auto-immune problems and reactions too much exposure can cause. She, in concert with her vet's advice, said to only give the DHPP (NO lepto and NO coronavirus). Since she gave a written 3 year health warranty, I don't want to do anything against her recommended protocol. I was speaking with another breeder before choosing the one we bought Bandit from who would void her warranty if you went outside her vaccination protocol and it was very minimal as well....in fact, even less vaccines than the breeder I chose.

My breeder had her vet give the first DHPP shot at 8 wks, then he was to have another at 12 weeks, another at 16 weeks and then wait until 20 weeks for the rabies. Then, at one year of age, he'll get a DHPP booster, a 3 year rabies, and then nothing else for at least 3 years. However, I will have to do the DHPP annually, I have since learned, to comply with his health insurance.

For heartworms, a monthly preventative is good. I use flea and tick preventative (advantix) because we have a lot of fleas and ticks here. The risks NOT protecting the dogs from those are too great. I had my collie wind up with tick paralysis this summer due to a tick that he got even WITH the protection.