Buy off of intraday quote or end of day prices.

Do you think it matters if I make key list purchases off of intraday quotes or wait for end of day prices.   I have primarily been a value investor and am trying to branch out into swing trading.  I know I may be able to get some better executions if I buy intraday but if I go with end of day I will be exposed to less noise.  Regardless of entry I am thinking of setting stops of not more than 2 ATR and having no expected losses of more than .5% of account (unless gap down occurs).     Does this sound reasonable?  Thanks for your thoughts. Law Lindsey