There is no 7-day PH only PHPs. The closest that you could come to a 7-day PH would be to purchase 2 4-day PHs at a cost of $204.48 per adult pass when purchased in advance from Disney. A 7-day PHP would be much cheaper even if purchased at the gate ($350.40).
If there is a chance that you will be returning in less than a year, you might want to consider purchasing annual passes. There are no "plus" features on a regular AP. For an adult, the cost is around $393. There is also the potential to save on your room if you're staying onsite and an AP code comes out.
Lastly, the 30-day Fun in the Sun pass runs about $315- $335 for an adult. It includes unlimited admissions to all 4 of the major parks, WWoS, DQ and PI plus a few places outside of the "world" for 30 straight days. Plus they include a breakfast voucher. If you can find a ticket broker who has passes available for your dates, this would be the least expensive way to go.