Interesting! One of my buddies made up kind of a similar game back in high school (80's) and called it Furnace.
5 card draw w/ a "stud-like showdown", hi/lo/sweep, no qualifiers for hi or lo, queens are wild, A-5 is best low and straight.
Deal 5 cards & Bet.
Draw (you can't see what you draw!). If you want to make it a positional advantage game, then dealer chooses how many to draw last, otherwise, everyone simultaneously declares (e.g. with a die) how many cards each person wants to discard/replace .
Since the reveal will take place card by card, you arrange your known cards in the order you want them to be shown and whatever you draw (unknown cards) go underneath, all face down.
Everyone reveals first card & betting round - action is on highest value exposed card(s). Continue until 4 cards are exposed with 1 hidden hole card.
After the 4th card betting round, players can choose to either replace a card (up or down - if down, you can't look at it) OR look at their down card - but not both. Either action costs a set amount of $ (looking is usually 2x the price of replacing). Again, if you want to make it positionally advantageous, you can go around the table twice - first time around for whomever wants to buy a card, starting with the player to the left of the dealer and finishing the transaction/replacement before moving to the next player; second time around for whomever wants to look at their hidden card, again, in order. Otherwise, to make it more equal, 1 chip for buy, 2 chips for look, no chips for "pat" - and everyone who is replacing tosses their cards before the first replacement card is dealt.
(Fwiw, you might want to pay to replace a card instead of drawing if you've got 4 good cards and one throwaway and you put the throwaway somewhere in the first 4 cards - then you buy it and see what you get right away. You might want to pay to look if for example you have a hand that could potentially sweep but you don't know what your last card is.)
After that supplemental action - you can choose to add one more betting round or just go straight to declare (1 chip lo, 2 chips hi, 3 chips sweep)...
