back yard gene hacking?

assume a well funded group, with staff and equipment.  (For example, look 
at someone like Aum Shin Ryko cult managing to aerosolise Anthrax into air

for 24 hours.)

How hard is it for them to get a bunch of virus / bacteria / fungal spores

and 'gene hack' them into something really vicious - spreads like measles,

infects about 80% of people it contacts, kills 60% of infected within 4 
weeks, leaves the rest immune from future attacks, but with severly 
compromised breathing (eg COPD) and with other weaknesses.

Obviously I don't want anything that can help real terrorists (I'm in the 
UK, and that stuff is illegal over here) but a list of dificulties they're

run into would be useful.