Not likely for perfect results, if any results. But if its free for you to try, go for it. If you have a DirecTV receiver it will give you the correct coordinates for your entered location.
The dish reflectors are engineered to specific angles to aim/reflect the incoming signals into the LNBs. So unless the Voom brand reflector is very close to exactly the same; I suspect you will just be asking for more headaches than just buying the correct dish; they are not expensive so why not just do it right.
I assume you are talking about a PhaseIII type LNB? and I bought my backup off of ebay for $50 shipped.
A new PhaseIII is $60 and the AU9 "SlimLine" 5LNB model is $100 retail.