SO 30 DIVES UNDER YOUR BELT, thus you have some knowledge of equipment. first your regulator. you mantioned atomic or mk25. my first was a mk25 the best breathing of all my regs..... i also have a m1 atomic. if you look at the atomics and you will see little difference in the models. they recommend to be serviced every 2 years as opposed to 1 year. its the metal in hte reg. they are all good in my opinion. as for scubapro you can look at a mk 20 also it is basically the same as the mk25 and perhaps a bit cheaper. other major brands i cant comment on.
bcd's .... ok this is a big area. first are you going to dive a lot or a few times a year? i have had both the jacket and the back inflate. the back inflate did throw me on my face till i adjusted the weight position to the back of the harness to take care of it. i use a dive rite transpac. next do you think you are going to go to doubles some time. if so look at a back plate and get some advice from the backplate community. they are pretty inespensive perhaps under 125.00 the money is in the wing. perhaps 2-300 can get a good one. once again get some advice on size from the backplate or techie folks. another thing to look at is if you are going to model your diving on the DIR principals. if so gear gets more specific. some folks agree and some dont with dir. the thing is if you are going to do this start with the right basics and expand as apposed to rebuying every year or so.
some things i believe in is
if you use a computer make it an air integrated one i use a tank transmitter to avoid the leash effect of the hp hose.
have your rig flexible enough accomodate the spectrum of diving you will be doing.
lightly read up on hogarthian diving. dont overload on the crap you carry with you. take only what you need.
being non fully DIR compliant is OK. you will surface again.
always use a weight belt even if it only has a couple of lbs in it.
figure out what is you most personal gear and own it. computer , reg , bc ,mask. rent the other stuff to start.
more bucks does not necessarily buy better stuff.
learn theory and use toys to confirm. or buy toys and use theory to confirm.
go for function not asthetics.
one surface for every dive
practice/ do something new on each dive and log it.
perfect your skills at your own rate
if you go with a backplate you will be comfronted with the question of al or steel. this will depend on the amount of weight you carry. steel is a lot heavier than al. when steel goes on an equal weight in lead must come off to comp. when you get gear make sure you can try it ( in a pool) to see if it works for you. shoes dont dance the same on the floor as they do in the store. or most peoples ex's were once really fine people.
fins there is a lot of controversy on split of non split. figure what kind of kicks you do ,, do you dive in currents or still water. and sadly what are the fins your buddies are using that you dive with.
thats probably enough to start with
good luck.
