This is exactly my setting for e-uae 1.0.0 no jit.
I'm using this setting for workbench wirth wdhload.
It gives me fullscreen but the Amiga image is not stretched.

cpu_type=68ec020
gfx_width=640
gfx_height=256
gfx_lores=no
gfx_linemode=none
gfx_center_horizontal=smart
gfx_center_vertical=smart
gfx_fullscreen_amiga=no
gfx_fullscreen_picasso=no
amiga.use_overlay=yes
amiga.screen_type=custom
sound_bits=16
sound_channels=stereo
sound_frequency=44100
cpu_speed=4
chipset=aga
fastmem_size=8
chipmem_size=4
z3mem_size=8
floppy_speed=800
show_leds=true