This topic pops every now and then, but if you don't have your molecular biology skills nailed down pretty hard you won't really go that far. FYI, yeast is far better to grow rather than ecoli. yeasts can fold and tolerate eukaryotic proteins better. They also smell far better (ecoli smells like shit, plain and simple). And you can always claim you're brewing beer.

Going to technical details, cloning genes and transforming cells is the lulz part, no difficultly here. But to get a micro-organism expressing these genes, in the appropriate amounts and without creating toxic metabolic by-products you'll have figure things like:

1. where in the genome you're going to stick these genes?

2. you'll need microorganisms (be it ecoli or yeast) that can be selected for during transformations. you might need to do some extra work to generate a strain that will be used for your future transformations.

3. which promoters will you choose to drive their expression? Some are too good, some are too bad, others just right (for each gene)

4. how are you going to ensure genetically modified organism are treated and disposed properly (even from laymen)

5. where will the end-product be? If it's inside the microorganism, it'll be most likely deleterious. And if it's well tolerated, boiling masses of yeast/ecoli bloody stinks like sewers. If it's outside in the medium all is well, but how are you going to do it? Targeting proteins to the secretion pathway is good idea, usually difficult to achieve in practise, but doable. Even in this case where you plan to synth dmt ex-vivo in the growing medium it'll be difficult to make both enzymes to work well. On the other hand, targeting dmt for secretion is another tedious story, almost undoable ATM;.

All in all, not a bad idea such a project takes time (I'd give it 1-2 years to achieve), loads of money and a full-time work on that, realistically.  

lol, noob

primer design (for the cloning stuff you propose) is easy as fuck!