Those tins may very well be useful for you, but last I checked many of those were slowly being phased out of the top-tier because of a new broken card: Deoxys EX, which boosts every Plasma Pokemon you have on your field other than other Deoxys EX cards. It's potential has been format-destroying so far, especially when partnered with Thundurus EX, and other players may absolutely hate you for using it, but it's also the most expensive card in the format aside from Tropical Beach, so it may be out of your price range. One purchase you should look into to get energy is the Elite Trainer Box, as that contains 40 total energy cards, damage counter dice, a coin-flip die, and 7 booster packs, a cardboard deck box, as well as the box it all came inside being able to be used as a collection case.
As for trainers, Pokemon Catcher is one of the best trainer cards around, but it runs $20 apiece, and that means $80 for a playset of just 4 when buying singles. That card comes within Emerging Powers. If you played back in the Base Set days, you may remember Gust of Wind, which is exactly how Pokemon Catcher functions. It's a very broken and format-breaking card, making evolution decks near impossible to play competitively. Catcher is found as an uncommon in Emerging Powers and a secret rare in Dark Explorers. It is possible the card may not be play legal when the format change is announced, seeing as it was printed in the 2nd and 5th oldest sets currently play legal, meaning it might not be worth sinking $80 into a playset right now, but if it stays legal that price could very well go up after the new rotation is announced. It's a staple in most competitive decks right now.
For draw trainers, your staples to consider are N, Professor Juniper, Colress, Bianca, Bicycle and Cheren.
Professor Juniper is best for sheer draw power at 7 new cards in your hand, but the drawback is that you have to discard your previous hand to do so. That drawback, however, can be negated by cards that take advantage of what's in your discard pile. Juniper is available as an uncommon in both Black & White and Dark Explorers, and as a full art "ultra-rare" in Plasma Freeze. Juniper is a Trainer - Supporter class card, and takes up the Supporter slot for the turn it is used.
Cheren is good for stable draw power and is more versatile than Juniper if you have some pieces you need in your hand but not all of the pieces yet, but might not be fast enough for setup in some decks and against some decks at only 3 new cards in your hand. You do not have to discard with Cheren, however. Cheren is available in Emerging Powers and Dark Explorers as an uncommon, and as a full-art ultra-rare in Boundaries Crossed.
Bianca is more situational, needing you to have fewer than 6 cards in your hand to be used for draw power, but only being most effective when you've got 2 or fewer cards in your hand. Bianca is available as an uncommon in Emerging Powers and as a full-art ultra-rare in Boundaries Crossed.
Colress gets better the fuller both benches are, merely requiring you to shuffle your current hand back into your deck to draw enough cards equal to the total number of Benched Pokemon in play. It is available as both an uncommon and a full-art ultra rare in Plasma Storm.
N is most powerful as a disruption tool if your deck is a slower starting deck. It's effect is to have both players shuffle their hands into their decks and then draw a number of cards equal to their own remaining prizes, and its effect is more amplified in the later game when one or both players has two or fewer prizes left. It is available in Noble Victories as both an uncommon and a full-art ultra rare and in Dark Explorers as an uncommon.
Bicycle is basically a less powerful version of Bianca, drawing until you have 4 cards in your hand, so it's much more situational, but it happens to be a Trainer - Item class card unlike all the other trainers above, so it merits a mention simply because of that.
--- cutting off here for further analysis later when I have more time ---
