The First Thing that must be clear before any negotiations happen is that the Pakistani Military will have a say; therefore I hope their is a military representative as part of the delegation that will be visiting next week.
The way I see it, Pakistan doesn't
need a deal, if it is not recognized China is providing some reactors, which will meet some our current needs. Pakistan is not limited by any treaty for inspections of military sites (nor should it sign one), and its ambiguity in numbers, and mixture of delivery systems keeps the world guessing and the pretense of deterrence viable.
But if there has to be any thing negotiated now, the current US administration is in the mood to negotiate, which Pakistan hasn't seen the likes of since the Reagan years., and before than the Pre-1965 years, so this might be a once in a generation chance.
Pakistan will need an expansion at a reasonable cost, and quick timetable of an increase in electricity generation. China's waiver may limit it to its current 2 new reactors planned for Chasma and possibly 2 at Karachi. Pakistan is looking into mining its coal reserves, and burn the coal in coal fired plants, that will generate a lot of carbon emissions. It is in the best interest of the US and Pakistan, for Pakistan to spend that money on more efficient and Modern American and European Nuclear Power plants, than on Chinese coal fire plants. (this type of deal would also be similar to india's and be a defacto recognition of pakistan as a nuclear weapons state)
Secondly, Any Cap on the numbers in Pakistan's arsenal are irrelevant to the issue of America's fear about tactical devices. Pakistan has unofficial agreed to limit the range of its missiles to those focused on India and not beyond, staying within its region, as not to get entangled in america's core interest/ally in the region. this should not mean that Pakistan does not continue to upgrade the quality of its delivery system, because that will be essential to maintain credible minimum deterrence as India buys means to thwart the current systems deployed. Also any future civilian space launch program should be SEEN as just that, civilian, and not in secretly trying to develop longer range systems, that could also be left open to inspection as a bargaining chip of the military sees that as necessary to make the deal i'm about to describe go through. This has been Pakistan informal assurances to the US, and should be seen as a signs of trust that Pakistan recognizes that core interest of the US.
What could be negotiated is Pakistan limiting its devices to missile systems with ranges of at least 200 km, so as not to confuse short range systems with being nuclear armed. but this would give up the defense to cold start, and the US can offer to supply Pakistan with the conventional means to thwart a full fledged cold start scenario; armored thrusts and waves of fighter-bomber attacks; with Apache or Cobra helicopters, more F-16's, upgrades including AESA Radars, and SAM / Radar Systems to maintain a credible defense, all these with associated support and ammunition (such as the sensor fused weapon) and spares.
this would be similar to the Egyptian deal for just enough defense against Israel
Also The US could supply equipment to defend the perimeter of all major army, navy, and air force bases in Pakistan to prevent theft or sabotage. perimeter defense equipment to prevent another kamra airbase incident, except this time a base which might have strategic assets.
more joint training for Pakistan's internal intelligence agency, to make them a better police/fbi force to catch those who may threaten these assets would also help, along with sale of surveillance gear to help them keep up with potential base attackers
this would be a comprehensive means to meet both Pakistan and the US needs on these issues, without compromising Pakistan's strategic ambiguity in numbers and prevent inspections or any such deal.