Aww! I think I was at a show in May or June or something. I was on MF Let's Get Rocked for one show for his english debut, but he was sold (congrats Rock!) in July.
I know where you're coming from with multi-discipline trainers: I ride with Mikell Farm Performance Horses and I couldn't be happier anywhere else! But I'll have to leave when I go away for college in about 3 years :'(
But I can help you with shows! There aren't many good "schooling" shows in the winter, but there is a series I'm going to called Jack Frost Jubilee. It has EVERYTHING! That'll be fun. Google it and it's at Crescendo Training Centre in Ephrata. Swan Lake has their winter series, but that's more of a higher-end show. I haven't been to Bridge Acres yet but I really, really want to next year, if I can.
For summer series:
Wellsville English Affaire hunter series. I love that place!
Shadowbrook at Gettysburg
Quentin Riding Club in Lebanon- they have a bunch of classes and it's really nice there. Definitely going back next year
Swan Lake- they have shows year-round
Windswept Acres at Stonetown- they do strictly jumpers and they're over in Reading, but it's very laid back and I had a blast
Twin Brooks- like a Columbia, but they have jumping as well. It's in Harrisburg
Not a series, but Keystone International Livestock Expo has an open show at the end of September. It's big, some of the H/J classes had more than 20 riders and the pleasure flats had upwards of 40, but still an excellent experience. It's at the Farm Show complex!
Look in the Equine Marketer and their website. They have many, many shows by month and that's where I found most of these! I'll try to think of more and put some more out there for ya!
Odd how we can wake up in five seconds at 3:30 for a horse show, yet barely be able to drag ourselves out of bed when we get up for school/work between 5 and 7!