Graduation Cash, what to do??

Well I am graduating from college and I know I will have some cash. There is some equipment that I have yet to aquire in my quest for aquarium success. Some things I would like to get are either upgrades to what I currently have or I dont have at all. First Ill brake down what I have already and the upgrades I would like then ill list some equipment I dont have and would like. Keep in mind that upgrading the size of my tanks is not an option.

Already have and the upgrade

(1) 5lb co2 - upgrade to a 10lb
(2) CO2 reg with no solenoid - upgrade and buy the solenoid
(3) 2x13w AHS and a 2x13w spiral compact over my 10g - upgrade to a 36w AHS

What I dont have and want

(1) RO/DI unit 25gpd-50gpd. Maybe larger is better if I upgrade my tank size later
a. If I get the RO/DI I will add some of those nicer softwater plants
(2) CRS shrimp. Probably S+ - SS. I once had them and failed but now I know my mistakes
(3) Glass double drop checker from GLA

Let me know what you think.