I would skip thinking about Ikelite not because it is a bad brand (i had 3 housings and where pleased with them, many very good photographers are using it with great results)
but you wrote that you would like to go deep 70m is not deep for most of other brands (around 80-90 is a standard now)
Ikelite takes a little bit more space due tho their design so it is not so good if you traveling that was one of my main reasons to switch
think more about kind of work you would like to do underwater are you in macro?, people?, wrecks? lots of traveling or meaby photos more from your backyard (some lucky bastards have nice diving places 10meters from their homes
)
there will always be a main income maker for you, main client maybe,
remember that sometimes you are assigned cause you made some particular kind of job for someone and were recommended for someone looking for same kind of job/style
that will narrow your equipment necessity field
other than camera equipment worth considering is rebreather, more time underwater more time for taking pictures
try to build your system on will it pay for itself terms then you will survive
and rember you have to eat too 
If You are in it as a Pro in spe remember that You will have to backup everything with another part of the system so it goes at least in pairs, not mentioning orings and accessories that should go in dozens 
every part of equipment brakes in most unfortunate moments the same about computers cards, phones, clothing too
- it is all your equipment if you cant do the assignment without it (try doing it without pants 
never go cheap but do not overinvest
should be one of your mantras
in my "abowewater
" company we have 18 yrs old canon and nikon telephoto lenses that costed a fortune but worked through 18 yrs of heavy usage on olympics so they paid their own bills many times since purchasing
DO NOT BUY cheap memory cards, readers, cables, batteries, orings - small things may ruin your assignment the same as big stuff failure