Printing at a full scale professional print shop will give you the best results. They've usually been in the business for decades and they know everything there is to know about printing. You can usually rely on any advice they give you.
Keep in mind, you'll want to start this early just in case their turn around times aren't very quick.
File type to use
These shops will usually prefer the JPEG file so go ahead and download that from your Templett account. They will also want full bleed so be sure to check that as well. These shops require a 300 dpi file and that's no problem because every JPEG and PDF from Templett is 300dpi.
We always recommend at least 100lb card stock for cards and anything printed that people will hold in their hands. Your finished result will have a higher quality feel.
We also recommend getting a sample pack from the printer so you can see and feel what 60lb, 80lb, 100lb, linen, gloss, matte, etc are like. This will give you a better idea what to go with.
The print quality should be excellent from any professional print shop. They typically use the best printing technology.
You don't need to worry about trimming because they will handle all of that. You'll get all of your cards in the exact size you order them.
Summing it up
We believe this is the best route to take to get the highest quality prints. It could (but doesn't always have to) take the longest time so start early. Get samples early so you can see and feel what different card weights and finishes feel like.