I don't think its possible to get 4 weeks hold with a glue? But ultrahold might be your best bet. I usually order 64 base with 1" SFS for frontal hairline and I find this combo the best. At the age of 27, a 65% density might be your best start for a first piece depending how thick your sides are and then adjust higher or lower density for your second piece. You may also think about getting hilights.