Both these cards are unfortunately pretty expensive on the market today thus you may consider to add some other Ruby and Emerald cards that can benefit from any Song or action that has been played like Roxanne or that can add some Aggro to your decklist like Cursed Merfolk, Ursulas Handiwork
I tend to play the slower power levels our format offers, both on our own platform and in my local game store, and while good tutors arent banned in those environments, you will hear the table collectively groan or mumble when a best in slot tutor gets cast
Also, combining with Deathtouch makes it more challenging for the opponent to block effectively
Arcums Astrolabe seems to me like a pretty easy card to play four copies of
Yes, Time Stretch was originally a flashback card (again, back then the mechanic was known as "salvage")
4 Ursula - Sea Witch Queen 208/204, Amethyst It's a bit of a shame that Ursula doesn't manage to top her own themed Ursula's Return expansion in value, but she comes close enough to it