Crikey, you are getting the miles on!! The car was serviced with an oil change the week before you bought it from me.
I have always used fully synthetic oil, and for the last 2 years have used Castrol RS oil which is 0W40. You will need 6 ltrs to include the oil cooler and pipework etc.
Before I used Castrol RS, I used Mobil one 0W40, so for 5 yrs it has always used 0W40. Some say that this oil is a bit light, but hey, it suits the car and it runs well. You could go to say a 10W40, if you are concerned, but its up to you. Castrol RS oil is now out of production, but you can buy it (sealed container of course)still on the like of e-bay at a good price since the replacement is 0W30.
I run my Phase2 V6 on 0W40 also, and it has never let me down. If its good enough for F3 cars, then its good enough for my car!
The oil filter you need, I have a few new ones left over (K+N Gold HP1002). If you want one or any of them, let me know by PM, since you need an oil filter for the oil filter re-loaction kit and not for the car. The one you need must have a NRV and is the one for the Supra TT J90. The Grexx one from Greddy cost £35.00 each. I can do the K+N ones delivered for £15.00 each.
I also have one of the spare wheel lock nut keys at home, so let me know your address by PM and I can send it to you.