Yes the wood can come from any source. It doesn't really matter to me. I am sure the final bill would be a little higher due to the extra shipping cost of just a single piece of wood.
Here is a list of the required size needed.
Tube, Cone and Tip
Indulgence - 1 1/2 x 6
XL3 - 1 3/8 x 6
XL3 Mini - 1 3/8 x 5
E-power and GoGo - 1 1/4 x 5 1/2
Tube and Cone
Indulgence 1 1/2 x 5 1/2
XL3, (tube and cone) 1 3/8 x 5 1/4
XL3 Mini, (tube and cone) 1 3/8 x 4 1/4
E-power and GoGo (tube and cone) 1 1/4 x 5
Tube
Indulgence 1 1/2 x 3 3/8
XL3 - 1 3/8 x 3 3/8
XL3 mini - 1 3/8 x 2 3/8
The only source I would not recommend for stabilized wood is Ebay. People try to stabilize wood at home which doesn't work well and turns the wood to junk. Some of these people sell this wood on ebay.
If the wood is not stabilized it needs to be dry. If I receive wood that is not dry I will not turn it. This will result in you waiting until the wood is dry enough to turn. This can be months. Stabilized is always ready to use.
The main requirements hinge around the drip tips as they match the cone and battery tube.
I would highly recommend using stabilized wood as this prevents swelling.
Wood species that I will not make drip tips out of because of safety reasons.
Avodire irritant, nose bleeds, internal bleeding, asthma
Cedar, Australian Red irritant, asthma, violent headache, giddiness, bronchitis, stomach cramps, NPC (rare)
Cedar, Western Red irritant, sensitizer, asthma, nervous system effects, NPC (rare)
Greenheart sensitizer, wheezing, splinters go septic, cardiac and intestinal disorders
Jacareuba irritant, fainting, insomnia, kidney damage
Makore irritant, nausea, headache, giddiness, nervous system and blood effects
Mansonia irritant, sensitizer, nausea, sneezing, headaches, nosebleeds, splinters go septic, asthma, giddiness, cardiac disorders
Milky Mangrove sap is poisonous, causes irritation to eyes and/or temporary blindness, headache, burning of throat, blistering of skin
Missanda irritant, headache, giddiness, nausea, disorders of bowels and stomach
Mulga(Acacia aneura) irritant, headache, nausea, wood contains a virulent poisonous principle used for spear heads by aboriginals
Opepe irritant, sensitizer, nervous system effects
Poison Walnut bark irritating to skin, dust may cause asthma, nausea, giddiness, sap is toxic and corrosive
Sassafras sensitizer, nausea, respiratory, direct toxin, NPC (rare)
Wenge irritant, sensitizer, splinters go septic, nervous system effects
Exposure is from the wood dust and oil. When these woods are stabilized I doubt there would be any issues. On top of that they are sealed in CA. But just the thought of someone getting sick from one of my mods turns my stomach. I want everyone to enjoy their mod and not wonder why they don't feel well. I really wish sassafras was not on the list I love that wood.
Everyone should also know that any wood can cause a allergic reaction to a very very small percentage of people. I listed the bad ones from what I have read. If you are exposed to the wood dust or oil and happen to be in the very very small percentage you may have symptoms such as rash, runny nose, congestion and sneezing. With wood that is sealed and stabilized you are not exposed to the wood, but I feel you should be aware anyways.