Well I'm not the best expert but I do have a good grasp on some things.
The Bonuses that I use are:
Sporty Sorts
Grace and Glory
Speediest
Fit and Fearless
Teh Smarts (Not really necessary)
Magically Mighty
Savvy and Scrappy
Longevity
Tenacious Trainer
Better Breeder
My Skills:
Breeding
Horsemanship
English Training
Sport Training
Veterinary Medicine
Farrier
The guide that got me started in Foxhunting was:
viewtopic.php?t=98375 Since then I have tweaked things for my own method. But this is still a great way to get started.
In my opinion Shekeira has the best lines. GPS is the brand to look out for. Pretty much if you're competing against a GPS horse, don't expect to win. Phantom Racer also has some really nice lines.
Like I said, I'm not all knowing when it comes to TBs but I have done my homework and I hope this answered a few of your questions
