Firstly, welcome to seibertron.com!
Warning: Seibertron.com may contain nuts!Now to your question:
A good deal of the ones you've mentioned haven't come out yet, or are unlikely to be made.
Autobot - Brains (TF 3) no word if this is going to be made
Autobot - Dino (Mirage?) (TF 3) coming soon
Autobot - Que (TF 3) coming soon
Autobot - Wheelie (TF 2,3) should be easy and cheap to get online, get the legends class one, it's closer to scale with the main toy line, the deluxe is huge
Autobot - Leadfoot (TF 3) coming soon
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Decepticon - Crowbar (TF 3) currently only Cyberverse Legion, should be available locally
Decepticon - Hatchet (TF 3) currently only Cyberverse Commander, also easy to find
Decepticon - Driller (TF 3) unlikely to be made
Decepticon - Devastator (TF 2) Two options, Legends Class which is more movie accurate in combined mode and amount of Constructions, Supreme Class large but simple both I believe cost about the same now though
Decepticon - Frenzy (TF 1, 2) Comes in TF1 Barricade and Human Alliance Barricade, there is also a horrible looking Fast Action Battler, but ignore that one.
Decepticon - The Fallen (TF 2) Best one currently is the NEST version with Staff and removable face
Decepticon - Igor (TF 3) unlikely to be made
Decepticon - Jetfire (TF 2) best one is the Takara Buster version that comes in the two-pack with Buster Optimus Prime, but it's expensive
Decepticon - Long Haul (TF 2) the original Voyager is amazing
Decepticon - Megatron (TF 1,2,3) Easy and cheap to get mostly, TF1 is the Leader Class Premium version best, might be really expensive now though, ROTF also Leader Class but there is no Premium here, TF3 currently only the Voyager best version of that is the one that comes in the expensive History set
Decepticon - Ravage (TF 2) Get the original release of the deluxe figure, most screen accurate and it's pretty cool
Decepticon - Soundwave (TF 3) There are two versions to get here, the ROTF deluxe preview figure and the upcoming TF3 deluxe.
As in places to get them, try BBTS
http://www.bigbadtoystore.com/bbts/They sometimes have great deals on figures and are having a sale right now, you might get something for cheap. Right now they have Scorponok for the cheapest I have seen him in ages:
http://www.bigbadtoystore.com/bbts/prod ... ode=retailAlso these guys are cool for loose figures and parts sometimes:
http://www.transformerland.com/Then there is our buy/sell/trade forum
carbombya-buy-sell-or-trade-f36.htmlJust start a thread asking for the ones you need, you might find a good deal by one of our members.
Happy hunting