I have been very happy with the Biocube HQI.
Just a few observations/recommendations if you decide to go with Biocube:
1) The Light fixture creates a lot of heat. I keep my house at 72 and have challenges keeping the tank temp below 82. I have managed this by keeping the Lighting period under 6hrs and partially sliding the Glass canopy forward to allow for air exchange.
2) You may want to add more flow: I added a Tunze nanostream 6045
3) Biocube Skimmer=Not so good. Some have had success, most have not. IMHO there are more efficient ways to export nutrients(Macro Algae, Water Changes) from a 29g tank.
4) Use the Refuge: I would recommend putting some Chaeto in the refuge chamber. The JBJ Refuge Led Light is a great addition and will provide sufficient light for your macro algae
5) Get an RO/DI unit. I know it's an additional expense but it will provide you long lasting benefits. (This really applies to any tank you get)
I bought my HQI from Marine Depot. There may be some Memorial Day sales still going on so I would suggest you review the Vendor forums here at RC and do some price comparisons.
Hope this helps