Welcome to ECF, Bear...
It's getting harder and harder to recommend atomizers and power supply devices... there are so many variations with such minor, but sometimes important "features" that - selecting something from, literally, the thousands of options has become a fool's blurry game, unless you know exactly the type of performance you're looking for.
Most recommendations you may get will be based on someone's personal experience, with only one or two choices... frequently none of which may be the way to go, for your particular needs.
When you use the term "digital", what you really want to say is "regulated". That's the separation... unregulated and regulated.
With an unregulated mod, be it tube or box, the current output is determined by using the atomizers resistance, along with battery voltage, run through an Ohm's law formula to determine two things... the output wattage, and does the battery(s) provide enough continuous discharge current to support the resistance without overheating the battery. Builds must be optimized to match wattage output, to obtain best performance.
With a regulated device, the wattage value applied to an atomizer is entirely of your choosing... up to and including maximum output. You can "force" wattage above the value that an unregulated, Ohm's law mod would allow... allowing you to cheat, and compensate for a build that is less than Ohm's law optimal.
They also allow you to easily fine tune the vapors levels of perceived temperature and flavor... which is just one reason why they are so popular - well, that and all the built-in user safety features. You don't need to have good battery/Ohm's law/mathematics knowledge to produce a good vape.
Here's a (short and certainly incomplete) list of RDAs that I've taken from
FastTech... all of which I have some experience with, and would be good, relatively inexpensive clone RDAs to consider. All of these are intended as more mid sub-ohm "flavor" rather than deep sub-ohm "cloud" type RDAs.
SoF
Rogue Styled RDA Rebuildable Dripping Atomizer
22mm, SS (w/ brass + copper top caps)
SKU 1980600: Ships next day $10.98 $10.98
AEOLUS Style RDA Rebuildable Dripping Atomizer
22mm, SS, Silver
SKU 1997300: In stock $10.98 $10.98
Nomad Style RDA Rebuildable Dripping Atomizer
22mm, SS (SS drip tip)
SKU 2033504: In stock $8.31 $8.31
Buhawi Styled RDA Rebuildable Dripping Atomizer
22mm, SS
SKU 2080401: In stock $12.34 $12.34
AEOLUS Styled RDA Rebuildable Dripping Atomizer w/Heat Sink Base
22mm, SS, Black (w/ heat sink)
SKU 2324601: In stock $10.10 $10.10
Foggatti Styled Switch Blade Dripper
22mm, SS
SKU 2328200: Ships next day $10.79 $10.79
REM Atty Styled RDA Rebuildable Dripping Atomizer
22mm, SS
SKU 2445800: Ships next day $11.33 $11.33
Mrs. Soaky Styled RDA Rebuildable Dripping Atomizer
22mm, SS
SKU 2446000: Ships in 5 business days $13.47 $13.47
Velocity Styled RDA Rebuildable Dripping Atomizer
22mm, SS
SKU 2482500: Ships in 3 business days $8.60 $8.60
VC Vecter V2 RDA Rebuildable Dripping Atomizer
V2, 22mm, SS - B
SKU 2537900: In stock $11.81 $11.81
NextGen Styled Genesis RTA Rebuildable Tank Atomizer
SS + Glass Tanks - B
SKU 2588900: Ships in 5 business days ETA: 9/16/2015 (3 days) $15.73
Production Styled RDA Rebuildable Dripping Atomizer
22mm, SS
SKU 2656800: Ships in 7 business days $7.80 $
Nectar Styled Genesis RTA Rebuildable Tank Atomizer
22mm, SS + POM, Silver
SKU 2830800: Ships in 5 business days ETA: 9/16/2015 (3 days) $10.72
Le Magister Styled RDA/RTA Rebuildable Dripping Atomizer
22mm, 316 SS, Silver
SKU 3047000: Ships next day $11.43
Aromamizer V2 Styled RDA Rebuildable Dripping Atomizer
V2, 23mm, SS + Glass, Translucent
SKU 3430803: Ships in 5 business days $10.64
Snapdragon Styled RDA Rebuildable Dripping Atomizer
22mm, 316 SS
SKU 3749700: Ships in 7 business days $17.33
Hazz V2 Dripper Tank Styled RTA Atomizer
V2, 22mm, 316 SS + PC
SKU 3752100: Ships in 7 business days $17.06
AX1 Styled RDA Rebuildable Dripping Atomizer
22mm, 316 SS
SKU 3752300: Ships in 7 business days $16.01
K.loud+G Styled RTA Rebuildable Tank Atomizer
K.loud + G, 316 SS + PEEK, Silver
SKU 3752400: Ships in 7 business days $19.99
Nectar Micro Styled RDA Rebuildable Dripping Atomizer
Micro, 22mm, 316 SS, Silver + Blue
SKU 3755600: Ships in 7 business days $14.86
Good luck...