...that current charger you detail only goes up to 35v so no it wont be ok.
From your #7 post it does look like you have 8 strings of 10 in series, and that they are all cross connected, presumably for thermal coupling reasons.
I hope they are all matched leds.
Could you give the datasheet as Ronv said, so that we can see if the voltage limit of the above supply, is enough to drive your leds in worst case Vf. (having said that it does look like a cree xp-g)
The "binning and labelling" document for xp-g leds from cree says max vf is 3.75v at 350mA....Gregory you are running these at 750mA each, so your vf max will be around 3.9V lets say......that means your led bank voltage is 39V plus any cabling losses.
...that current charger you detail only goes up to 35v so no it wont be ok.
If you wanted to try the PCB , then the following "creating circuit boards with eagle" is a good guide to doing it, and the eagle layout program is free for boards which are double sided and less than 8cm by 10cm.
https://tangentsoft.net/elec/movies/
The hysteretic buck using hv9910b is the simplest form of led driver, and has few parts, so its a long shot, but might just be do-able. the gate drive is weak and so youll get a fairly less snappy dv/dt on the drain voltage , easing layout.....I would say just get all the power components reasonably tight and just go for it.
I am sure Gregory knows the structure of a pcb......if double sided , then its just a piece of fibreglass with copper tracks and pads on the top and bottom. The pads have solder resist around them to prevent shorting to other pads, and there is "silkscreen" lettering so that you know what the components go where. If connection to the bottom layer is required then you go through a via, which is a hole pated with copper.
Anybody who understands the basic structure of the pcb that they want, and who can use a windows pcb, can use eagle to lay out a pcb. Youtube has some good vids on it.
Eagle is that pcb layout package that really has no secrets and anyone can use it.