Why 1/2" ? 7/16" will work just as well and save you some money
. 1/2" is not really necessary.
Two different ropes would also be a good idea. For the spinnaker halyard
Samson LS or NER Sta Set will work fine. A little stretch will not cause any difficulty for the spinnaker but your jib halyard
should be low stretch. For the jib
halyard Sta Set X would do the best job unless you want to pay extra for one of the low grade Dyneema
ropes such as VPC. 7/16" Sta Set X is currently $1.86 at Jamestown. You might prefer VPC which at $1.79 with Defender is slightly less expensive. Ask them for a quote on Sta Set X which isn't in their catalog.
If you can wait a little while Defender will be having its annual sale
in late March and all ropes will be cheaper.