The key aspect is that if you (and your husband) are UK resident, then you are taxable in the UK. There are detailed rules for determining when your period of residence in the UK would be considered to start.
Under UK tax rules, husbands and wives are taxed independently. (Income from jointly held assets is divided equally.)
As an employee, you would be liable to UK income tax and National Insurance on your salary and benefits. These would be deducted at source by your UK employer. As you are moving with your present employer, there are special rules on National Insurance. You may wish to check whether your HR department is familiar with them.
Your husband should take advice about his business vehicle. He would be taxed in a straightforward way if he was a sole trader. Under UK tax rules, an US LLC is considered to be tax opaque, in other words taxed as a company. This gives rise to complications and unnecessarily onerous tax.
