that dont look so bad .. actualy I think that is right on ..
the intake hole in the bottom just need to be passive .. and in most case double the size .. so a hole the size of the outtake ventilation on each side at the bottom might work perfect (make sure they are light tight unless you do choose Autos ?)
also .. a thing I did .. and works pretty well .. I also have 2 passiv intakes .. but on one of them I did fit a 150mm tubeing and made it run up to my passiv intake over my window in the room (1,5M tube was enough for me as my room is near a window) that provide fresh air/co2 directly from the outdoors .. plants seems to love it .. did also make my temps go down 1-2C and I also love it as I dont have to leave windows open to provide fresh air .
actualy I also got a cheap (7£) bathroom ventilation..
to help pull even more fresh air in through the tube .. but one thing at the time ..
I reccon you want the two shelf then ..
and it look like you want a small shelf with a few T5HO to start seedlings (fist few weeks)
that also nice .. tho I bet you could still do two shelf and a shelf for seedlings (fist two weeks to cut the grow time from 8 to 6 weeks on the "real" shelfs)
but agin .. one thing at the time .. I bet that can work very well with just one shelf and one plant (two might be to croudy ?)..
and as I said .. it easy to shop and upscale later on when you have more experiance and money .. and know what you want ..
Im not to much in to LED .. but I know you want them 1W as they are the best/most effectiv I read .. dunno much more about em ..
just that some China made once is more toy then grow lights and some more expensiv big brands are realy good .. so dont go cheap on em .. do the research .. get some others have good experiance with ..
but yea Im sure LED and T5HO is the way .. if you have high temps and littel room ..
that system .. spot on ... with two LED shelfs (maybe with a extra T5HO fixture as side/back light) and the DWG running smootly and two nice Autos and I bet you can haverst +2 Oz evry 6 weeks .. if you at haverst have them 2 new small 2 weeks seedling ready from the small shelf ..
Ooh yea and make sure ther is about 30cm at the top of your room for ventilation and carbon filter ..
EDIT: thinking more about it and your space ..
60cm might just be perfect for two plants ...
if you choose small plants .. I reccon Autos would fit that purpose best .. also as they are fast .. and will give you less problems .. light leaks wont be a problem either .. just runn em 18/6 or 20/4 from start to finish like with the seedlings at top .. so no need to make that light proof either (would also be hard with one ventilation at the top)
if it was me ... with that set up .. I would try to find some 60 days wonders or another fast small auto strain and do it like on your picture with two small plants in DWG under the LED and when they are two weeks from havers I plant new seedling to have ready so they stay 2 weeks under the T5HO and 6 under the LED .. roughly ..