Hi mate !
Personally i would go for it, i've been thinking about this in the past, luckily i'm still in my job, driving a 7.5t van, delivering etc. and i'm seriously thinking of going for my hgv, spoke to a few drivers out and about, some say it's fine out there, some say it's getting tougher due to european drivers coming over and doing the job cheaper
I was looking into a driving agency that taught you, put you thro you're test and found you a job around your surrounding area , but would have to look into the fees, and how much would you have to pay back the agency !
As you say , you can sell you're supe , and after you're up and going, go out and buy another
Good luck !