There are two options: you can either make it smaller, or keep it at 60 cards.
Smaller decks (~35 cards) have an Entropy mark and are mainly fuelled by Supernovas for fast early-game bursts of quanta. Wins against FGs are faster, but win rates are a bit lower.
60-card decks are generally Time mark and have lots of card drawing and early-game stall to use before it gains control of the board. Win rates are higher, but wins against FGs are slower.
Suppose you want to go the 60-card Timebow route. Here's a general formula for building them.
Quanta Balance: Generally, a 60-card Timebow needs 22 Quantum Towers. Novas are rather useless for Timebows, so take those out.
Basic Defense: 6 Sundial, 6 SoG, 4-5 Phase Shields. These will help you stall the early game while you draw your combo pieces.
Card Draw: 5-6 Hourglasses. You need to go through as much of your deck as you possibly can while your stalling can still protect you.
Creature Engine: 2-3 Oty, 1 FFQ, 1 Druid, 1 Boneyard, 2 Bone Wall, 2 Rain of Fire, 2 Quintessence. Pretty self-explanatory if you've played with classic Timebows before.
Support Cards: 1 Pulverizer, 1 Eternity, Bond, possibly a PA.
Other Stuff: You could consider adding another Quintessence and a Crusader to be able to keep both weapon effects in play. Miracle + Heal for EMs and early-game survival. There's roughly 5-10 cards worth of customization in a large Timebow, so see what works for you.
Some sample reference builds (may be a little bit outdated, but still more recent than the SGbow):
Pervepic's Timebow (
http://elementscommunity.org/forum/index.php/topic,5814.msg67447.html#msg67447)
Seravy's Timebow (
http://elementscommunity.org/forum/index.php/topic,4666.0.html)